Minister for Justice Michael McDowell has rejected the statement by alleged IRA leader Thomas "Slab" Murphy that he had no connection with suspected money-laundering activities.
Mr McDowell said in his view Mr Murphy was a man whose credibility was "very minimal".
The Co Louth farmer issued a statement last week in the wake of raids on properties in Manchester and Dundalk by Britain's Assets Recovery Agency and the Garda Criminal Assets Bureau, in which documents were seized. He said he had no property interests and made his living from farming.
But Mr McDowell said he did not believe this. On the RTÉ Radio programme This Week, the Minister said: "Let's remember that he went before a jury in the Four Courts in Dublin denying that he had anything to do with the IRA, or that he was a leading member of the IRA - chief of staff of the IRA. The Sunday Times defended that case and a Dublin jury was quite convinced by the evidence that they received, that he was."
He added that, "sad to say, one of the witnesses who testified against him in the proceedings ended up dead just over the Border, shortly after that case was finished.
"He was chief of staff of what they describe as their army and he was for many, many years a member of the army council of the IRA. His credibility has to be taken in my view in that context."
The Minister also warned that all funds illegally accumulated by the IRA would be sought, by the Criminal Assets Bureau in the Republic and by the Assets Recovery Agency.
"There is no amnesty for the vast amounts of money that the IRA have squirrelled away. They will be sought wherever they are, in Ireland or abroad. There is no question of the Provisional movement being able to hold on to vast resources which they have accumulated over many years through crime."
Asked about the Independent Monitoring Commission's report, Mr McDowell said it would be presented to Government this week and it covered a period prior to the IRA statement in July and "that colours the background situation".
He believed the statement of July 28th and the decommissioning that followed "affords potential for a huge improvement in the situation in Northern Ireland and dramatic transformation of the involvement of paramilitarism and politics".
